Combination lock mechanism



Aug. 26, 1969 E. H. LEBLANC COMBINAT ION LOCK MECHANI SM 4 Sheets-Sheet 1 Filed Feb. 1, 1967 INVENTOR.

EDWARD H. LEBLANC ATTORNEY.

Aug. 26, 1969 E, H. LEBLANC COMBINATION LOCK MECHANISM 4 Sheets-Sheet 2 Filed Feb. 1, 1967 INVENTOR.

EDWARD H. LEBLANC ATTORNEY.

Aug. 26 E. H. LEBLANC COMBINIKTION LOCK MECHANISM Filed Feb. 1, 1967 4 Sheets-Sheet 5 INVFNTOR.

H HEEE o EDWARD H. LEBLANC E. H. LEBLANC Aug. 26, 1969 COMBINATION LOCK MECHANISM 4 Sh-ets-Sheet Filed F'eb. 1,.1967

H LEE 0 41- 0 Q 2 Q M T VB 1 60 A 9 8 4 V 88 INVENTOR.

EDWARD H. LEBLANC ATTORNEYS.

United States Patent 3,462,981 COMBINATION LOCK MECHANISM Edward H. LeBlanc, Cromwell, Conn.

(2944 Hopkins Ave., Redwood City, Calif. 94062) Filed Feb. 1, 1967, Ser. No. 613,168 Int. Cl. EtlSb 37/16 US. Cl. 70-156 12 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a combination lock mechanism utilized to secure doors in dwellings and actuate automobile ignition switches without the need for keys and more specifically a novel combination lock mechanism which does not employ conventional tumblers but utilizes axial members which are positioned by depressing buttons, for example, on a doorknob in proper sequence to unlock the door.

Combination lock mechanisms for doors, per se, are old and many designs are well known in the art, however, to my knowledge none of these designs have ever been successfully manufactured or sold to the public. It appears that one or more of the reasons for the shortcomings of the combination door locks known in the prior art are their bulk, complexity of design, susceptibility to diagnosing the combination and the ability to be overridden by the use of force. I believe the combination door lock that I have conceived utilizing pushbuttons in the manner described below has overcome all of the shortcomings previously described, namely is readily adaptable to conventional door knobs, is a simple design, is foolproof and cannot be opened by use of force. It is these features which will make my combination door lock most desirable both from the design and commercial viewpoints. Therefore a particular feature of my invention is a cylindrical housing enclosing my combination lock mechanism which is smaller than the conventional doorknobs and easily adaptable to such doorknobs.

A further feature of my invention is that the cylindrical housing carries a series of axial elements for actuation by pushbuttons located on the doorknob. Proper depression of the right buttons in sequence causes incremental movement of said elements which releases a latch plunger to engage a latch actuator. It should be noted that prior to depressing the pushbuttons in proper sequence the latch plunger and latch actuator are not engaged. Therefore as an important feature the doorknob is free to rotate when the door is locked and therefore the door cannot be opened by forcing or twisting the doorknob.

As a further particular feature, I prevent the ability of one not familiar with the proper sequence from diagnosing the proper combination by means of automatically resetting the axial elements to its original position at any time the wrong button is pressed regardless of the number of increments the axial members have moved prior to depressing the wrong button. Those skilled in the art will appreciate that this novel feature will frustrate the attempts of one attempting to diagnose the proper combination by trial and error.

3,462,981 Patented Aug. 26, 1969 Another important feature of my invention is that the door can easily be locked or opened from the inside of a dwelling by simply depressing a single button located on the inside knob. A slight depression of the inside button will close the door and further depression will open it.

The more important features of my invention have been outlined broadly above in order that the more detailed description that follows may be better understood. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto.

The objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is an exploded view showing an outside doorknob and the mechanism of my lock.

FIGURE 10! is an exploded view showing an inside door knob, latch case and housing for the mechanism of my lock.

FIGURE 2 shows a cross section of my combination lock mechanism and knobs.

FIGURE 3 shows position of my mechanism with the door locked.

FIGURE 4 shows an incremental movement of one of the elements in my mechanism.

FIGURE 5 shows my mechanism engaged for opening the door.

FIGURE 6 shows the mechanism repositioning itself upon depressing the wrong pushbuttons.

Referring to the drawings which illustrate preferred embodiments of the mechanism constructed in accordance with the present invention, FIGURES 1, 1a, and 2 show the general arrangement of the combination lock mechanism and a doorknob assembly which includes an outside doorknob 10, a combination lock mechanism housing 24 attached to knob 10 by means of four blind rivets 30, a door latch case 26, mounted in door 28, and a latch actuator 32 attached to the lower portion of inside doorknob 34 by means of screws 36. Shaft 40 communicates with the inside doorknob 38 and outside doorknob 10 by passing axially and centrally between both knobs and axial along the curved inner portion of latch actuator 32, through opening 42 of latch case 26. Shaft 40 is supported at the inside doorknob 38 by engaging and being threaded into the internally threaded button 44 centrally located on knob 38. It is slidably supported at its other end by engaging the inner portion of the knob anchor 46 which is peened to outside knob 10 through the central opening 48.

It should be noted that the lower portion of inside doorknob 34 can be manufactured as an integral portion of doorknob 38, but in my present embodiment it is attached to doorknob 38 by means of four screws 50. The doorknob 38 is attached to inside flange 52, by sliding the flange 52 up against shoulder 54 of the lower portion 34 and then placing snap ring 58 in groove 56 so that the flange 52 is secured to lower portion 34 by abutting shoulder 54 on one side and abutting snap ring 58 on the other side. The inside doorknob assembly including the latch actuator 32 and shaft 40 and button 44 is mounted to the door 28 through opening 60 by means of two screws 62 which pass through flange 52, opening 60 and engage the two blind threaded holes 66 in outside door flange 64 on the opposite side of the door. Outside doorknob 10 and housing 24 abut the outside flange 64 at shoulder 68 on one side, and plate 70 attached to housing 24 by four screws 72 abut the inside of flange 64. It should be noted that both the inside doorknob 38 and outside doorknob 10 are free to rotate in the manner that they are assembled and attached to door 28.

Having so far described the shell of a more conventional doorknob assembly, we shall now proceed to the combination lock mechanism located in housing 24 and outside doorknob 10. Referring to FIGURES l and 2, a plurality of apertures 22 located around the outer edge of knob receives a series of pushbutton assemblies. In my embodiment six apertures are shown to receive six pushbutton assemblies. Each ushbutton assembly consists of a cup 12 which receives a spring 14 and inserted through the center of spring 14 is a pushbutton 16 wherein the shoulder 74 abuts against the right end portion of spring 14. The left end portion of pushbutton 16 has a threaded hole 76, and this end portion has a diameter which slidably fits hole 78 in the bottom portion of cup 12. Finger 18, which is made of spring steel, is attached to the underside of cup 12 by screw which engages threaded hole 78 on pushbutton 16. This assembly is then press fit into aperture 22 until the upper lip of cup 12 abuts the periphery of aperture 22. Finger 18 is so designed that the inclined hooked portion engages a slot 80 in cylindrical guide ring 82. There are six such slots located around the surface of ring 82, one for each finger 18. Guide ring 82 is urged rearward towards knob 10 by spring 84 agaist shoulder 86. Spring 84 abuts rim 88 on stationary housing 24 at its other end. Pin 90 is press fit into housing 24 and engages slot 92 on guide ring 82 and acts as a stop to keep guide ring 82 from being urged completely rearward. It also keeps the guide ring 82 from rotating relative to housing 24. Guide ring 82 slidably engages the outer surfaces of segments 94. There are six such segments 94 interlocked to form a hollow cylinder. In each of these segments there is a slot 96. Slots 96 are laterally displaced a discrete distance from one segment to the next. It should be noted that each slot 96 is radially aligned with a given slot 80 on guide ring 82, although it is laterally displaced from these slots. Similarly each finger 18 is radially aligned with a given slot 80 as shown in FIGURE 2. Segments 94 are urged forward by spring 98 against the outer lip of cup 100. The cup 100 is freely mounted so that it engages the end of guide ring 82 on the underside of its lip at 102. The inner surface of cup 100 is aligned with the inner surface of segments 94 so as to form a continuous surface. Spring 98 is softer than spring 84 so that the resultant effect of these two springs, without any outside forces acting upon the elements, is to keep guide ring 82 in its rearward position. The continuous surface formed by the inner surface of cup 100 and segments 94 slidably engage the outer surface of latch plunger 104. Latch plunger 104 is a hollow cylinder which has three tabs 106 bent over at its forward end, each of these tabs 106 is located at intervals of 120 degrees around the periphery of the forward end of latch plunger 104. Latch actuator 32 is formed by a curved portion of metal forming slightly less than a 120 degree are which readily can engage latch plunger 104 between two of the adjacent tabs 106 thereon. Since alignment between the tabs 106 and latch actuator is important, latch plunger 104 is kept from rotating relative to latch plunger guide 110 by pin 108 which is press fit in latch plunger guide 110 and engages slot 112 on latch plunger 104. Latch plunger 104 is slidably mounted on the otuer surface of latch plunger guide 110. Latch plunger guide 110 is brazed at its rearward end to doorknob 10. Spring 114 which abuts the forward end of latch plunger guide 110 at one end and against washer 116, which is press fit against shoulder 118 on latch plunger 104, at its other end, tends to urge latch plunger 104 forward. However trigger spring 120 is mounted in such a way as to keep latch plunger 104 in its rearward position having a hook portion 122 engaging hole 124 in latch plunger 104, while its sloping portion and rear end hook 126 in slot 128 embrace the rear of latch plunger guide 110.

As previously mentioned, shaft 40 is supported by button 44 at the inside knob 38 and also supported by knob anchor 46 at the outside knob 10. Knob anchor 46 is of a cylindrical hollow shape with its rearward end closed, and nestled in this hollow portion is spring 130 against which the end of shaft 40 abuts. Mounted around shaft 40 is the trigger release 132 which is a hollow cylindrical cup having its outside surface slidably engaging the inner surface of the latch plunger guide 110. The trigger release 132 has a larger internal diameter at one end and a smaller internal diameter at the end which slidably engages shaft 40. Shaft 40 has two pins 134 pressed diametrically through its center so that portions of these pins extend equal amounts on both sides of shaft 40. These pins 134 are spaced a given amount from one an other with one pin located on the inside of trigger release 132 and the other outside and to the left of it. Similarly there are two pins 136 pressed into shaft 40 at a given amount apart, one on either side of washer 116. The function of pins 134 and 136 and the reason for the spacing therefore will be described below. However, it should be noted at this time that these pins have a constraining elfect on shaft 40 from having excessive lateral movement.

The operation of my combination lock mechanism can best be observed by referring to FIGURES 2, 3, 4 and 5. FIGURE 2 shows the position of the elements of my mechanism when the door has been locked. As will be described later, the door is locked from the inside of the door. With the door in the locked position, latch actuator 32 and latch plunger 104 are disengaged so that the outer doorknob rotates freely when one tries to open the door without applying the combination. The inner doorknob 38 will always open the door when it rotates because latch actuator 32 engages the opening 42 in latch case 26. One proceeds to open the locked mechanism by depressing one or more buttons 16 in the proper sequence. Buttons 16 may have numerals, letters or other marks on their faces so that a person knowing the combination can identify the proper buttons to be pressed. -Upon pressing a proper button 16 (please refer to FIGURE 3), as indicated by the arrow, finger 18 moves laterally to the left. Since finger 18 is designed so that it is urged downward (as indicated by arrow in FIGURES 2 and 3). As it moves toward the left it will slide off the top of one of the segments 94 and into slot 96 as indicated in FIGURE 3. Upon releasing button 16, it will return to its original lateral position (please refer to FIGURE 4) thereby also moving the segment 94 an equal distance to the rear with it, since hook portion 138 engages the rear side of slot 96. The elements are so designed that when pushbutton 16 has returned to its original lateral position, the sloping portion 140 of finger 18 is resting against the inclined shoulder 142 of slot in guide ring 82. By thus moving segment 94 an incremental portion rearwardly against spring 98, all the segments 94 move an equal distance rearwardly since they are interlocked. When these segments 94 are so moved rearwardly another slot 96 in one of the segments is aligned beneath one of the slots 80 in guide ring 82. In order for another finger 18 to engage the slot 96 now aligned beneath slot 80 one must press the proper button 16 in the sequence of the combination. Let us assume that the proper button is now pressed, then the motions described above upon pressing the first proper button 16 will be repeated. However, as soon as the second proper button 16 is pressed and finger 18 engages slot '96 and starts to move it rearward an additional incremental distance, the first finger 18 will ride up against inclined shoulder 144 of the first slot 96 and disengage first segment 94. Similarly upon pressing the proper button 16 for the third time in sequence, elements 94 will move an additional incremental distance rearwardly. Upon pressing the proper number of buttons 16 in sequence, segments 94 will have moved a sufiicient distance to ride over and depress the U- shaped portion 148 of trigger spring which protrudes above latch plunger 104 in slot 146 (please refer to FIGURE 5). As the segments 94 depress trigger spring 120, the hooked portion 122 of trigger spring 120 is also moved downward out of hole 124 of latch plunger 104 and latch plunger '104 is shot forward by the urging of spring 114, to engage latch actuator 32. Upon engagement of latch plunger 104 and latch actuator 32 rotation of the outside doorknob will open the door. By rotating outer doorknob v10, latch plunger guide 110 rotates with it since they are brazed together, and the rotation of latch plunger guide 110 causes latch plunger 104 to rotate by means of pin 108 which engages slot 112. Since the latch plunger 104 is engaged to latch actuator 32, rotation of the latch plunger 104 will cause tabs 106 thereon to rotate latch actuator 32. Rotation of the inside doorknob 38 at any time causes the latch actuator to rotate, and since it always is in engagement with opening 42 in latch case 26, its curved portion is cammed against a surface in such a manner to open the door.

Upon release of the latch plunger 104 and shooting it forward, its forward end engages the bottom of cup 100 and moves it forward to a given distance. The movement of cup 100 causes guide ring 82 to move a similar distance since the lip 102 on cup 100 engages the forward end of guide ring 82. Guide ring 82 moves forward against spring 84 and as it so moves, any finger 18 which may have engaged slots 80 or 96 are disengaged therefrom and are moved up by the action of inclined shoulder 142 on them and also rest on shoulder 142 as shown in FIG- URE 5.

It should be noted that the arrangement of segments 94 and the corresponding axial position of the slots 96 thereon determine the proper combination to open the locked mechanism. Therefore, if one wishes to change the combination, one has to rearrange the segments 94 to correspond to the desired combination. Similarily, the initial distance the segments 94 are spaced from trigger spring 120 determines the amount of buttons 16 which have to be pressed and present in the combination to open the mechanism. As a preferred embodiment, I have chosen a set of segments 94 and their initial distance from the trigger spring 120' in such a manner that three buttons 16 have to be pressed in the proper sequence to actuate the mechanism to open the door.

Previously we have assumed that the proper combination was known, and that pushbuttons 16 were pressed in proper sequence to open the combination door lock. Let us now assume that at any stage of pressing buttons 16, the wrong button was pressed. Referring to FIGURE 6, let us assume for example that a proper button 16 has been previously pressed (bottom portion of FIGURE 6) and engaged slot 96- in segment 94 thereby moving segment ring 94 rearward an incremental distance against spring *98. Now upon pressing the next button which is not in proper sequence (top portion of FIGURE 6) finger 18 will fall into slot 80 of guide ring 82, but since slot 80 is not aligned with slot 96 of segment 94 the lowermost portion of finger 18 will ride on the surface of segment 94. The hook portion 138 of finger 18 will abut the forward end of slot 80 forcing guide ring 82 forward against spring 84. This motion of guide ring 82 forward will release any finger 18 which may be engaged in slot 96 by causing such finger to ride up on sloping portion 140 (lower portion of FIGURE 6). Therefore, segments 94 will be repositioned to its original position, before any buttons 16 are pressed, by the action of spring 98 moving it forward until it abuts the lip of cup 100. Upon releasing the button 16 which was not pressed in proper sequence (upper portion of FIGURE 6) guide ring 82 will be returned to its original position by action of spring 84. The mechanism has now been completely repositioned and one may start the combination sequence again. It should be noted that this repositioning will occur at any time of the cycle. That is, regardless whether it is the first, middle or last button which is not pressed in proper sequence, the mechanism will reposition itself when the wrong button is pressed.

As was mentioned earlier, thecombination lock mechanism may be locked and also opened from the inside knob 38. This is accomplished in the following manner. First assume that the combination lock mechanism is open, FIGURE 5, and we shall close it from the inside. By depressing button 44 on knob 38, shaft 40 will move toward the right against spring 130- in knob anchor 46. As shaft 40 moves toward the right, the left pin 136, of the pair of pins 136 on shaft 40 which is in engagement with washer 116, will cause latch plunger 104 to move rearwardly until trigger spring is repositioned in the latch plunger 104 as shown in FIGURE 2. That is the hooked portion 122 of trigger spring 120 engages hole 124 in the latch plunger 104 and U-portion 148 of trigger spring 120 protrudes above the rear end slot of the latch plunger 104. Normally one will close the lock mechanism, as described above, and then swing the door shut as they go outside.

Now, if the combination lock mechanism is in the closed position, one may open it from the inside by further depressing button 44 on the inside knob 38. As can be seen in FIGURE 3, further movement of shaft 40 to the right will move latch plunger 104 against trigger spring 120 by the action of left pin 136 against washer 116. This will attempt to depress trigger spring 120, but due to the design of this spring, U-shaped portion 148 will abut the shoulder in slot 146 and resist being depressed. However as shaft 40 is moving toward the right, left pin 134 of the pair of pins 134 comes into engagement with the forward end of trigger release 132 and begins to move it rearward. The movement of trigger release 132 rearward causes the rim 150 on trigger release 132 to abut the lower sloping portion 152 of trigger spring 120. Continued movement of shaft 40 to the right causes rim 150 to depress trigger spring 120 so that latch plunger 104 is now freed from hook portion 122 of trigger spring 120. As soon as this occurs, latch plunger 104 is freed and shoots forward to engage the latch actuator 32. It should be noted that the two pins 134 are so spaced on either side of the trigger release 132 so that upon releasing pressure on button 44 there is a time lag before right pin 134, by action of spring on shaft 40, engages trigger release 132 to move it forward away from trigger spring 120. This is done to assure that latch plunger 104 has had sufficient time to shoot forward before trigger spring 120 is allowed to move up again. For if trigger spring 120 moved up too soon, hook portion 122 might again engage hole 124 and keep latch plunger 104 from shooting forward to open the mechanism.

It has thus been described how the combination lock mechanism may be opened or closed from the inside of the door. Whether the mechanism will be closed or opened from the inside depends upon the amount button 44 is depressed. If the mechanism is locked to begin with there is no problem as to how much the button 44 has to be depressed. However if the mechanism is Open, depressing the button a small amount will close the mechanism and further depression will open it. Now one may ask how do you know the amount to depress the button 44 to get the desired result. As can be seen from the previous description in closing the mechanism one presses button 44 against a spring 130 and a trigger spring 120 falls into place. The falling into place of the trigger spring 120 causes a definite audible click which can also be felt. Further depression of the button meets greater resistance by spring 130 and trigger spring 120 which is now also under pressure. One can therefore definitely tell by feel and hearing when the mechanism is locked and also tell by increased resistance that he has locked the mechanism and any additional pressure will open it.

While I have described the structure and operation of the combination lock mechanism of the present invention in considerable detail as applied to doors for purposes of illustration, it will be understood that many of these details may be varied considerably and my combination lock mechanism may be utilized in ways other than doors such as automobile ignition switch actuation,

without departing from the spirit and principles of my invention.

I claim:

1. A combintion lock mechanism which engages a latch, said mechanism comprising a casing, a plurality of pushbuttons mounted on the face of said casing and each adapted to be depressed from a normal projected position to a fully depressed position and upon release to be returned to its initial projected position, a stationary cylinder mounted in and affixed to one end of said casing, a latch plunger slidably mounted on said cylinder, biasing means urging said latch plunger toward one end of said casing, means for holding said latch plunger in a retracted position, a latch actuator rotatably mounted in the other end of said casing, means for releasing said latch plunger and shoot it toward one end of said casing to engage said latch actuator upon completion of depression of said pushbuttons in proper sequence.

2. A combination lock mechanism as defined in claim 1 wherein means for holding said latch plunger in a retracted position is a spring.

3. A combination lock mechanism as defined in claim 2 wherein each of said push buttons has a finger attached at its end located in said casing.

4. A combination lock mechanism as defined in claim 3 wherein means for releasing said latch plunger comprises a series of interlocked elements slidably mounted on said latch plunger and each having an opening therein and each opening cooperating with a corresponding finger upon depression of the proper pushbutton in proper sequence.

5. A combination lock mechanism as defined in claim 4 wherein the cooperation of a finger and an opening in one of said elements upon release of its corresponding pushbutton moves said elements against the action of said spring retracting means.

6. A combination lock mechanism as defined in claim 5 wherein completion of depressing the pushbuttons in proper sequence moves said elements to a position where it disengages said spring retracting means and thereby allowing said forward biasing means to shoot said latch plunger toward one end of said casing and means for resetting said elements to its original position upon depression of a pushbutton in improper sequence.

7. A combination door lock mechanism comprising a door lock, a knob which is free to rotate at all times attached to said door lock, a plurality of pushbuttons peripherally mounted around the face of said knob, first means for unlocking said door lock mounted in said knob and door lock when said knob is rotated atfer completion of depression of said pushbuttons in proper sequence, said means comprising a series of coaxial elements, a latch plunger, a spring cooperating with said plunger and at least one of said coaxial elements, and second means for resetting first means to its original position upon depression of a pushbutton in improper sequence.

8. A combination door lock mechanism as defined in claim 7 wherein said latch plunger is biased to move in one direction but is constrained from moving by said spring.

9. A combination door lock mechanism as defined in claim 8 wherein said pushbuttons have fingers attached to the ends thereof located inside said knob, and each of said pushbuttons are adapted to be depressed from a normal projected position to a fully depressed position and upon release to be returned to its initial projected position.

10. A combination door lock mechanism as defined in claim 9 wherein several of said coaxial elements are interlocked and each has an opening therein which cooperates with at least one of said fingers upon depression of the proper pushbutton and moves a given distance against the action of said spring upon releasing said depressed pushbutton.

11. A combination door lock mechanism as defined in claim 10 wherein completion of depressing the push buttons in proper sequence moves said interlocked coaxial elements to a position where it disengages said spring thereby allowing said latch plunger to shoot toward the direction in which it was biased to engage a latch actuator rotatably mounted in said door lock.

12. A combination door lock mechanism comprising a first doorknob having a plurality of pushbuttons mounted on its face, a second doorknob, a casing containing a door lock attached at either end to said first and second doorknobs, a door lock closing and opening mechanism mounted in said casing, a spring mounted at one end of said door lock closing and opening mechanism, a release mechanism axially mounted in said door lock closing and opening mechanism, an opening in said second doorknob having a button mounted therein, a shaft which is attached to said button, said shaft cooperates with said release mechanism at a point intermediate the ends of said shaft and also abuts against said spring which biases said shaft toward said second door knob whereby, depressing said button a given distance against said spring closes the door lock, and further depression of said button actuates said release mechanism to open said door lock.

References Cited UNITED STATES PATENTS 545,666 9/1895 Barney -220 545,667 9/1895 Barney 70-220 1,480,760 1/1924 Hill 70-220 1,691, 28 11/1928 Schlage 292-169 2,165,067 7/1939 Pfendner 70-214 2,640,346 6/1953 Grifiin 70-313 FOREIGN PATENTS 209,638 1/ 1924 Great Britain.

MARVIN A. CHAMPION, Primary Examiner EDWARD J. MCCARTHY, Assistant Examiner US. Cl. X.R. 

